The present invention relates to a pneumatic tire and a tire/wheel assembly which enable run-flat traveling, and more specifically, to a run-flat tire and a tire/wheel assembly in which the workability of tire-to-rim fit has been improved.
To meet the demand from the market, numerous techniques have been proposed to enable a certain degree of emergency driving even when a pneumatic tire is punctured while driving a vehicle. Among those numerous proposals, the techniques proposed in Japanese Patent Laid-Open Publication No. 10-297226 and Published Japanese Translation of a PCT Application No. 2001-519279 enable run-flat traveling by fitting a core to a rim in a cavity of an assembled pneumatic tire and by supporting a flat tire with the core.
The foregoing run-flat core has an open-leg-structured circular shell including a support surface thereof extended toward the periphery of the tire and leg portions along each end of the support surface. The run-flat core is constituted by having elastic rings attached to both of these leg portions so that the core is supported on a rim through the elastic rings. The advantage of the run-flat core is that the available rims and wheels in the market can be used as their own, without any particular modification. Thus, the core can be accepted to the market without causing difficulties therein.
When fitting the core in the tire/wheel assembly, first, the core is inserted into the cavity of the pneumatic tire, and the pneumatic tire needs to be fit into the wheel rim while containing the core. However, there has been a problem that it is difficult to perform tire-to-rim fit since the core is able to freely move in a tire radial direction in the cavity of the pneumatic tire. Moreover, there has been another problem that it is hard to stably seat the elastic rings on rim humps.